Abstract
The phytoremediation potential of Dracaena reflexa to remediate diesel contaminated soil was determined in a greenhouse study. D. reflexa was planted in soil contaminated with different concentrations of diesel fuel (1, 2.5 and 5 wt%). 5 (wt%) of three different organic wastes [tea leaf (TL), soy cake (SC) and potato skin (PS)] were mixed with the soil and monitored for 270 days. The results of the biodegradation of oil and its fractions showed a reduction of 90 % and 98 % of total petroleum hydrocarbons (TPHs) in soil amended with SC, at 2.5 % and 1 % fuel, respectively. It was observed that in the non-cultivated polluted soil the TPHs, were reduced by 24-27 %. Soil amended with SC provided the greatest diesel fuel loss when compared to other organic waste supplements. D. reflexa roots did not accumulate hydrocarbons from the soil, but the number of hydrocarbon utilizing bacteria was high in the rhizosphere, thus suggesting that the mechanism of the oil degradation was via rhizodegradation. This study has shown that D. reflexa amended with organic wastes has a potential for biodegrading hydrocarbon-contaminated soil.
